In so-called video-on-demand systems, video data are coded in a video-server and stored, and are transmitted to a customer upon request via a broad-band cable distribution network. The picture information of the video data is divided into video pictures which produce a video film when they are placed together in sequence.
Due to the limited transmission capacity of broad-band cables, and above all the cables of the subscriber line network, a compression of the video data is performed by coding according to the interframe method, to reduce the data in the video-server. To that end only the difference in the video data of sequential video pictures are coded and stored, but not the video data of the original video pictures. When interframe-coded video data are transmitted, it is a disadvantage that they cannot be wound in a fast forward direction or in a fast backward direction because the picture information of the preceding video picture is always needed to create the present video picture.
From DE 38 31 277 it is known that intraframe-coded video data are inserted and stored from time to time in the interframe-coded video data stream. The intraframe-coding utilizes the video data correlation within one video picture. The bit rate of intraframe-coded video data is significantly higher than the bit rate of interframe-coded video data. A rapid forward or backward motion of the picture takes place through the separate reading and transmitting of the intraframe-coded video data inserted into the interframe-coded video data stream. A disadvantage of the method is that an increased transmission capacity is needed to transmit a video film.